My long-standing work with polymers has solidified my vision for the future—one centered on advancing sustainable materials for real-world impact and application. From early explorations in material science to later development of eco-conscious materials from lignin, I am committed to driving innovation in sustainable engineering, research and development. The expertise I have gained in polymer synthesis, production, processing, and characterization has prepared me for a career in polymer’ focused research and engineering. Moreover, with newly acquired skills in scale-up and commercialization, I am also confident I can conduct research that falls at the intersection of research and industrial application.
Research Interests
My research experience focuses on the sustainable valorization of lignin—an underutilized polymer in lignocellulosic biomass—through integrated approaches in recovery, purification, and chemical modification. I have specialized in advancing lignin separation processes, optimizing solvent-based fractionation methods to improve molecular weight and purity, and developing green chemical modifications to tailor lignin's functionality for material applications. By combining process engineering with comprehensive material characterization, I aim to expand lignin’s utility in high-value products such as carbon fibers, polymer composites, and polymer foams, while contributing to the broader goals of renewable materials research and circular bioeconomy development.
Lignin is an abundant biopolymer and cost-effective biopolymer (costing about $0.5-1 per kg), and valued for its high aromaticity, carbon content, and diverse functional groups such as hydroxyl groups and carbonyl groups. These attributes make it a promising candidate for replacing petroleum-derived precursors. Despite its potential, it is still underutilized due to drawbacks such as limited accessibility in the US, difficulty in purification, wide distribution of molecular weight (MW), low molecular weight (MW), and poor compatibility with easily accessible polymers.
To resolve these fundamental challenges, my work addresses these issues through the following research efforts.
1) Development and optimization of lignin recovery processes to improve the commercial availability of lignin: A major contributing factor to the high cost of lignin production is the separation step as lignin is extracted as fine particles that are difficult to filter and handle efficiently. To address this, I have worked on developing and optimizing recovery processes aimed at increasing lignin particle size while maintaining a balance between cost and product quality. This involves reactor design, process flow development, tubing sizing, and overall system optimization. These processes are tested using black liquor from both industrial and academic partners to show their viability.
2) Improving the properties of lignin using solvent fractionation with hot aqueous organic solutions: To improve MW and purity control, I utilize a physical fractionation method that utilizes inexpensive, green solvents (e.g., acetone, ethanol, and acetic acid) with water at elevated temperatures to form two distinct liquid phases: a lignin-rich phase and a solvent-rich phase. I investigate the effect of operating conditions on phase behavior, molecular weight (MW), and purity of the resulting lignin fractions. This work enables a deeper understanding of the thermodynamic interactions between lignin and various solvents, which can be leveraged to improve product quality. Using this approach, I have achieved molecular weight increases by a factor of 2–9, along with significant reductions in metal and sugar impurities, enhancing the suitability of lignin for high-performance material applications.
3) Improving the properties of lignin through chemical modification via esterification with citric acid: To further increase molecular weight and tailor polarity, I have explored polymer reaction and synthesis techniques aimed at improving material compatibility and polymer development. Specifically, this work involves interlinking lignin molecules through esterification with citric acid—a naturally occurring, non-toxic compound. This method not only increases molecular weight but also enhances compatibility with common polymers such as polyethylene and polystyrene by enabling better polarity control. As a result, significant improvements in lignin properties were achieved, including a sixfold increase in molecular weight, a 45 °C rise in glass transition temperature, and a notable reduction in polarity.
4) Comprehensive characterization of lignin to quantify commercial and molecular value: All extracted and modified lignins are systematically characterized using NMR (31-P, HSQC, 13-C), TGA, GPC, FTIR, DSC, and HPLC to assess MW, purity, functionality, and thermal properties. These metrics are essential for evaluating their suitability in downstream applications.
5) Utilization of lignin in the advanced products through collaborative efforts: Finally, I am working collaboratively to incorporate lignin into high-performance products such as carbon fibers, polymer foams, hydrogels, and membranes. These efforts aim to demonstrate lignin’s viability in real-world commercial and industrial applications.